hi finally got her started. Bought a new alfa starter from guy on ebay £79 next day delivery. Recommend him.
Firstly tools, make sure you have a 13mm ring spanner ... a short ratchet was very useful too.
Disconnect the battery.
Select first gear .... gives a couple of extra inches that makes a hell of a difference.
It can be done from the top easily enough, just remove all the plastic air pipes and box and disconnect the throttle body (can leave cable attached) and pull out of way. Unclip all pipes and cables from the throttle body clips. I have largish hands and its tight but doable. Unbolt the big cables from the starter and move away, disconnect the smaller cable. Now the hard bit ..... 'cracking' the bolts, they were VERY tight and took me best part of an hour to remove the 3 bolts ...... you also need patience .... lots ....
The short ratchet was very useful here but the 13mm ring spanner ESSENTIAL. When undone it takes a bit of wriggling and swearing but it comes out where the throttle body was easily enough.
refitting the new one is simply a reversal but its much easier to put the bottom bolt in first, as you can support the weight and find the hole ..... there is only enough room for one hand.
i bought a duff 2nd hand unit so did this twice, the second time took just 2 hours cos i knew what to remove and the bolts were already 'cracked' so they came staright out.
easy but fiddly job, patience essential. Hope this helps someone.